Digitizing tablet systems that allow a user to operate a computing device with a stylus are known. Typically, a digitizer is integrated with a display screen, e.g. over-laid on the display screen, to correlate user input, e.g. stylus interaction on the screen with the virtual information portrayed on it. Position detection of the stylus provides input to the computing device and is interpreted as user commands. Digitizing tablets configured for game applications are also known and typically involve detection of multiple objects positioned over the digitizing tablet.
U.S. Pat. No. 6,690,156 entitled “Physical Object Location Apparatus and Method and a Platform Using the Same” assigned to N-trig Ltd., and U.S. Pat. No. 7,292,229 entitled “Transparent Digitizer” also assigned to N-Trig Ltd., both of which are incorporated herein by reference in their entirety, describe a digitizing tablet system capable of detecting position of a user input, e.g. physical object, game pieces and/or a styluses, including an electrical circuit, either active or passive. Typically, the system includes a transparent digitizer overlaid on a Flat Panel Display (FPD). The digitizer includes a matrix of vertical and horizontal conducting lines to sense an electric signal passing through the vertical and horizontal conductive lines. Positioning the physical object at a specific location on the digitizer provokes a signal on the digitizer whose position of origin may be detected. Typically the game pieces and/or styluses receive an excitation signal from an excitation coil surrounding the digitizer or by horizontal and vertical coils embedded in the digitizer sensor. Each one of the game pieces and/or styluses is resonant at a different frequency and therefore can be identified.
U.S. Patent Application Publication No. 2007/0062852 entitled “Apparatus for Object Information Detection and Methods of Using Same” assigned to N-trig Ltd., and which is incorporated herein by reference in its entirety, describes a detector adapted to measure an output signal of a digitizer sensor associated with an object, wherein the output signal is an object information code. The object information code typically includes information regarding the position of the object as well as information regarding identification or orientation of the object.
U.S. Pat. No. 5,853,327 entitled “Computerized Game Board” assigned to Super Dimension, Inc., and which is incorporated herein by reference in its entirety, describes a computer game and board game including an apparatus for automatically and non-discretely sensing the location of toy figures relative to the game board and actuating an audio/visual display sequence in response thereto. Typically, each of the game pieces includes a transponder that communicates with an array of coils mounted on the upper part of the game table.
The use of Radio Frequency Identification (RFID) tags for identification is well known. Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a (RF) signal, and performing other specialized functions. The second is an antenna for receiving and transmitting the (RF) signal. These are operated in conjunction with a central unit which receives the RF signals and identified the object from the received signals.